Apparatus for machining pipes and the like

ABSTRACT

An apparatus for clamping and rotating workpieces such as pipes and for performing machining operations, such as pipes, in which the workpiece is clamped by devices which have clamp levers pivoted at their outer ends to a rotary housing and have their inner workpiece engaging ends inclined and in which the machining operation for cutting threads is carried out by cutting elements moveable radially on a support therefor. The cutting elements are spring biased toward retracted position and are held in cutting position by a stop element which is adapted to be moved to ineffective position by movement of a member which is engaged and moved by the end of a workpiece machined.

United States Patent [72] lnventor Artur Fohl llaubershronn, Germany[21] Appl. No. 753,615 [22] Filed Aug. 19, I968 [45] Patented Aug. 17,1971 [73] Assignee Rems-Werk Christian F 011 & Sohne Waiblingen, Germany[54] APPARATUS FOR MACHINING PIPES AND THE LIKE 4 Claims, 5 DrawingFigs.

[52] U.S.C1 10/107, 10/87, 82/42 [51] Int. Cl 823g 1/00 (50] Field ofSearch 10/87, 89, 90, 107; 77/73; 82/42; 279/106 [56] References CitedUNITED STATES PATENTS 2,768,550 10/1956 lngwer et a1. 77/73 2,962,92012/1960 Wallace 77/73 Primary Examiner-Charles W. Lanham AssistantExaminer-E. M. Combs Attorney-Walter Becker ABSTRACT: An apparatus forclamping and rotating workpieces such as pipes and for performingmachining operations. such as pipes, in which the workpiece is clampedby devices which have clamp levers pivoted at their outer ends to arotary housing and have their inner workpiece engaging ends inclined andin which the machining operation for cutting threads is carried out bycutting elements moveable radially on a support therefor. The cuttingelements are spring biased toward retracted position and are held incutting position by a stop element which is adapted to be moved toineffective position by movement of a member which is engaged and movedby the end of a workpiece machined.

PATENT-ED AUG! 7197:

SHEET 1 UF 4 ATENTFU Am; 1 71m SHEET 2 OF 4 Fig.2

In V617 for:

Jr/ur 7339/ APPARATUS FOR MACHINING PIPES AND THE LIKE The presentinvention concerns an apparatus for machiningpipes and the like, as forinstance for thread cutting, deburring, or cutting off, with a threadingdie head which is displaceable on frame means while the thread-cuttingtools of said apparatus are movable in a direction transverse to theirdirection of rotation and in their end position toward their axis ofrotation are adapted to be locked by means of arresting devices. Theapparatus is furthermore provided with a workpiece-chucking devicelocated at one side of the threading die head, said chucking devicecomprising in particular three clamping or chucking jaws pivotallysupported by a carrier while the curved clamping surfaces of saidclamping jaws are located eccentrically with regard to the pivot axis.The curved clamping surfaces are each provided with a recess engaged bya pin or the like of a control member which is movable relative to saidcarrier in a direction transverse to said recess.

Heretofore known devices of the type involved have the clamping jaws ofthe workpiece-chucking device designed as two-arm levers. One of saidarms comprises the clamping surface while the other arm has the recessfor engagement by the pin of the control member. As a result of thisdesign, the heretofore known workpiece-chucking or clamping devices haveunduly large dimensions which makes them complicated in structure.

It is an object of the present invention to provide an apparatus of theabove mentioned general type which will be simple in construction andfurthermore assure a safe and precise machining of pipes and the like.

It is another object of this invention to provide an apparatus as setforth in the preceding paragraph, in which the workpiece-clamping devicewhile having small dimensions will assure a firm clamping or chucking ofthe pipes to be machined.

These and other objects and advantages of the invention will appear moreclearly from the'following specification in connection with theaccompanying drawings, in which:

F IG. 1 illustrates partially in side view and partially in section anapparatus according to the invention.

FIG. 2 is a cross section through FIG. 1 along the line 11-" thereof.

FIG. 3 illustrates a modified threading die head according to theinvention as seen from the right with regard to FIG. 1.

FIG. 4 shows the threading die head of FIG. 3 as seen from the leftthereof. 7

FIG. shows a cutout of the threading die head according to FIG. 4 insection and in pivoted illustration.

A workpiece-chucking or clamping device according to the presentinvention for machining pipes and the like is characterized primarily inthat the clamping jaws form one-arm levers and that the recesses to beengaged by a pin or the like of the control member are located betweenthe pivot axis and the clamping surface. This arrangement greatlyreduces the dimensions of the workpiece-clamping device according to theinvention while assuring a safe operation thereof.

In order to permit a high clamping force in spite of the relatively weakdimensioning of the apparatus, each clamping jaw is supported by a cupof the carrier by means of a corresponding pin-shaped extension or thelike, said cup being located opposite to the clamping surface of therespective clamping jaw and preferably being of a semicircular contour.In order, when turning the control member by a relatively small angle,to obtain a relatively great feeding movement of the clamping jaws, therecesses in said clamping jaws are so designed that they extendapproximately radially with regard to the pivot axes in longitudinaldirection. It is also possible to provide the recesses on the controlmember in which instance the clamping jaws are provided with pins or thelike extending into said recesses. Furthermore, the control member maybe connected to the clamping jaws through simple levers or linkagemeans, as for instance elbow levers, in such a way that the clampingjaws will carry out a pivoting movement in response to a turningmovement of the controlmember.

In order after initiating the turning movement of the workpiece-clampingdevice to assure that the clamping jaws are firmly engaging theworkpiece, the control disc is connected to an adjustable friction brakepreferably in the form of a band brake, which extends around acylindrical portion protruding from the drum and pertaining to thecontrol disc and bringing about a relative movement of the control'discwith regard to the carrier for the clamping jaws until the clampingsurfaces of the clamping jaws engage the circumference of the workpiece.Inasmuchas the clamping surfaces of the clamping jaws are locatedeccentrically with regard to the pivot axes thereof, the clamping forceof the workpiece-clamping device automatically increases with increasingtorque acting upon the workpiece.

According to a further development of the invention, two axially spacedclamping devices are provided having their clamping jaws movableindependent of each other so that the workpiece can safely and in aplay-free manner he chucked. Inasmuch as the clamping jaws of the twoclamping devices are movable independently of each other, a firm hold ofthe workpiece within the range of each workpiece-clamping device will beassured without running the risk that the circumferential surface of theworkpiece will be damaged, inasmuch as the clamping force is distributedover two clamping areas. Expediently, the clamping devices are arrangedat the ends of a hollow shaft supported by bearing means. The hollowshaft is within said bearing means drivingly connected to a motorpreferably through a worm drive by means of which the workpiece-clampingdevice with the clamped workpiece is rotated. It is also possible,instead of the workpiece-clamping device, to rotatably journal thethreading die head and to connect the same with a drive.

The threading die head of the above-mentioned type of the device formachining pipes or the like has a control disc which is tiltablerelative to a cutting jaw holder and can be arrested by means of anarresting device. The said control disc is provided with recessesextending transverse to the circumferential direction thereof forengagement with pins or the like of the cutting jaws which aredisplaceable approximately radially. According to a further developmentof the present invention, such threading die head is so designed that asafe arresting of the control disc in cutting position will be assured.The present invention furthermore makes it possible that after apredetermined machining stroke, i.e. after a predetermined length of thethread has been obtained, the cutting jaws move automatically outwardlyso that their engagement with the workpiece will be interrupted. Thisinterruption of the cutting operation may be effected selectively byhand. The arresting device according to the invention is of a simpleconstruction.

With a threading die head of the above-mentioned type the inventionprovides that the control disc and the member supporting the same havean abutment, and furthermore provides that between the abutments aspacer member is movable by means of a control member which is locatedbetween the abutments of a releasing member which is movable transverseto the axial direction of the control disc and movably journaledthereon. The said releasing member has a feeler member by means of whichit engages a control surface of an abutment for the workpiece, saidabutment being displaceable with regard to the control disc. In view ofthe spacer member movable between the abutments, the cutting position ofthe control disc and thus of the cutting jaws is precisely determined.When the workpiece which during the thread cutting operation carries outan advancing movement abuts the above-mentioned abutment, the latter iscarried along by the workpiece so that the feeler member is actuated andthe releasing member is moved in its direction of movement. Thereleasing member then removes the spacer member from between the twoabutments so that the control disc and the members supporting the samecan be rotated relative to each other in such a way that the cuttingjaws are moved away from each other and disengage the workpiece. Afterthe said abutment has once been adjusted, i.e. threads with respectivelythe same length can be cut without a particular manual operation forstopping the thread cutting operation after the said thread length hasbeen obtained. Expediently, the control disc and the parts supportingthe same are preferably resiliently interconnected by screw pressureacting in circumferential direction in such a way that the control discin response to a relief of the spring is rotated relative to the controldisc supporting part in such a way that the cutting jaws are moved awayfrom each other.

The relief member of the arresting device according to the invention mayin a simple manner be formed by a tiltable lever which is preferablymovable between abutments and one side of which faces the spacer memberlocated between the abutments while the other side thereof faces thefeeler pin. In this way the construction of the threading die head canbe simple while the relief member can move the spacer member in a simplemanner out of its position between the two abutments of the arrestingdevice.

According to a further development of the invention, the abutment forthe support of the feeler pin has a circumferential surface which isinclined to the axial direction and the mantle lines of which convergeto that side which faces away from the oncoming side. Thus, the feelerpin may in a simple manner be displaceably arranged so as to be able tomove radially to the axially displaceable abutment in the control disc.I

It has been found advantageous to form the abutments for the spacermember by rollers so that the spacer members during its movement betweenthe abutments and during the oppositely directed movement will not beexposed to too great a friction. The construction of the arrestingdevice may furthermore be simplified by forming the spacer member by apart, preferably a cylinder member, which is freely movable in a cage.The axis of this movable member is, when located between the abutments,arranged along a straight line with the axes thereof. The spacer membermay, however, also be formed by a portion of a tiltably pivotallyconnected lever which may be linked either to the control disc or to thesupport therefor. Furthermore, it is possible displaceably to guide thespacer member in positive guiding means on one of the said two parts.

According to a further suggestion in conformity with the presentinvention, the control member is formed by a lever which is pivotallyconnected to the support for the control disc which forms one side of acage for the spacer member while the section which faces the support forthe spacer member is tiltable toward the abutments. By tilting thislever, the spacer member is moved between the abutments. 1

According to a preferred embodiment of the invention, the control leverand one abutment are mounted on one adjusting ring which in its turn istiltably and arrestably mounted in the housing which houses the supportfor the cutting jaws. Preferably, the said adjusting ring is tiltable inconformity with a scale so that the cutting position of the control disccan be adjusted relative to the cutting jaws.

For purposes of actuating the control lever, within the range of thelatter and preferably at the outside thereof, there is mounted a leverwhich is movable toward the control lever which latter is journaled on afixed part, preferably the housing, so as to be movable relativethereto. The said fixed part is preferably provided with a curvedabutment surface for the control lever which surface is curvedapproximately coaxially with regard to the cutting head axis and isprovided with a handle. By means of this lever, the control lever may beactuated in a simple manner at any relative position of the control discwith regard to the housing.

ln order to facilitate the introduction of the spacer member between theabutments associated therewith, the preferably two-arm control lever isprovided with a follower which in the tilting direction of the controldisc, for purposes of opening the cutting head, is located behind acorresponding abutment surface of the control disc. When the controllever is tilted, it first takes along the control disc by directengagement of the follower in the corresponding direction of rotationuntil during the end phase of this movement the spacer member. is

tuating shaft provided with a handle, said last-mentioned shaft beingjournaled in the housing. In this way by a simple turning of theactuating shaft by means of the handle, the control lever is tilted formoving the spacer member.

The operation of the threading die head is very simple when theactuating shaft which is approximately axis-parallel to the abutment forthe oncoming movement, is displaceable axially and through a linkage isconnected to the last-mentioned abutment. This makes it possible by anaxial movement of the actuating shaft to move the said abutment axiallywhereby, as described above, the spacer member is removed from betweenthe abutments so that the cutting jaws will automatically be moved awayfrom each other.

It is also possible by means of one and the same handle to move thecutting jaws into cutting position and also to their other end position.Advantageously, the handle is tiltable about an axis which is transverseto the actuating shaft and is linked to the actuating shaft while acounter bearing fixedly connected to the housing is located between thelinkage point and the handle.

In order to assure a safe mounting of the axially displaceable toolholder while preserving a simple construction of the device, theapparatus according to the present invention is so designed that atleast one tool holder, preferably the threading die head, the pipecutter and the deburrer are at one hand guided on a positive guidingmeans and on the other hand are guided on a substantially plane slidingsurface. In this way, without special steps, tolerances can becompensated for while furthermore an easy displaceability of the toolholder will be assured.

The positive guiding means may, in a simple manner, be formed by apreferably horizontal cylindrical linkage.

In order to be able easily to remove the individual tool holders or toarrange and exchange the same, the tool holders are detachable mountedon a sleeve displaceable on the cylinder rod.

Referring now to the drawings in detail, a device according to thepresent invention comprises a frame I mounted on detachably insertedpipe legs 2 in straddled position and carrying the support 3 which ispreferably a cast body.

One side of the support 3 forms a bearing housing 4 for twoworkpiece-clamping devices in the form of chucks, said clamping devicesbeing arranged coaxially with regard to each other at both end faces ofthe bearing housing 4. The other side of the support 3 comprises guidingmeans 7 for a threading die head 8 which guiding means extend parallelto the axial direction of the chucks 5, 6. The said other side of saidsupport 3 furthermore comprises a pipe-cutting device 9 on one side ofsaid head 8 and a deburring device 10 on the other side of said head 8.

The two chucks 5, 6 are of identical construction. As shown in FIGS. 1and 2, each chuck 5, 6 comprises a drum 11 which has that end facethereof which faces away from the bearing housing 4 closed by a discshaped cover 12 connected to said drum 11 by means of screws 13. Drum 11together with the cover 12 forms a housing which is substantially closedon all sides and the end faces of which have passages for the workpieceto be machined. Drum 11 is provided with a sleeveshaped extension 14which is guided in the housing 4 and by means of screws 16 is connectedto a hollow shaft 15 journaled in the bearing housing 4.

Arranged in drum 11 are three chucks 17 which are uniformly distributedover the circumference of said drum and are designed in the form ofone-arm levers while being pivotable about axes parallel to the drum 11.To this end, each chuck 17 has a pivotlike extension 18 supported on theinside of drum 1] by a bearing cup 19 of semicircular cross section. Thebearing cups 19 are provided on protruding reinforced areas of the innersurface of drum 11. Both end faces of the cylindrical pivot 18 of eachchuck 17 have a protruding pinlike centering extension 21. Thesecentering extensions 21 are journaled with play in correspondingcentering recesses 22 on the cover 12 of the drum and/or on the sideopposite to cover 12 in such a way that the stud or pivot 18 ofeachchuck 17 will be able over its entire surface to rest in the respectivebearing cup 19 pertaining thereto. On that side which is opposite thestud 18, each chuck 17 is provided with a curved clamping surface 23which is eccentrically located with regard to the pivot axis of therespective chuck 17 and which may be formed by a saw tooth-shaped gearring 24. When the chucks 17 with their clamping surfaces 23 engage thecircumference of a workpiece 25 indicated in FIG. 2 and inserted intothe chucks 5, 6, and if this workpiece 25 is under a load in thedirection of rotation indicated by the arrow 26, the chucks 17 will withincreasing torque be pressed at a higher pressure against thecircumference of the workpiece 25 so that the workpiece 25 will besafely held while the chucks 17 rest in the bearing cups 19. 1f thedirection in which the load acts upon the workpiece is opposite to thedirection of the arrow 26, it is merely necessary after loosening of thecover 12 of drum 11 to withdraw the chucks 17 from the bearing cups 19and to insert the same reversed so that the same effect will occur as itoccurred previously when the load acted in the direction of the arrow26. v

The chucks 17, which are arranged entirely within the drum -l1 closed atit circumference, have each of their side surfaces provided with an ovalgroovelike recess 27 which extends radially with regard to the pivotaxis of the respective chuck 17. The said recess 27 is arranged betweenthe clamping surface 23 and the stud or pivot 18 of the respective chuckpertaining thereto. The recess 27 of each chuck 17, which recess facesaway from the cover 12, is engaged with play by a pin 28 of a controldisc 29 located coaxially with regard to and in said drum 11. The disc29 may in a simple manner be mounted on the drum. The three pins 29associated with the chucks 17 are uniformly distributed over thecircumference of the control disc 29. The control disc 29 directlyengages those side surfaces of the chucks 17 which face away from thedrum cover 12. The control disc 29 is connected to a brake disc 30 whichis rotatably journaled outside the drum 11 on a sleevelike extension 14of the drum and is prevented from axial displacement. To this end, thebrake disc 30 is provided with bolt shaped members 31 which extendthrough slot-shaped semicircular recesses 32 in the end face of thedrum, the control disc 29 being drawn against the end faces of saidbolts 21 by screws 33. The brake disc 30 is located in a correspondingrecess 34 at the end face of the bearing housing 4 so that it isprotected. The circumference of the brake disc 30 is engaged by a brakeband 35 provided with a corresponding lining. The brake band 35 is bymeans of a bolt 36 in the bearing housing 4 secured against rotationwhile both ends of said brake band are adapted to be tensioncd by ascrew 37 extending tangen tially with regard to the disc 30 and held onthe bearing housing 4 in such a way that the friction can be adjusted atwhich the brake band 35 engages the brake disc 30.

When the chucks 5, 6 are turned relative to the bearing housing 4 in adirection opposite to the direction of the arrow 26, the control disc 29braked by the bank 35 will first not rotate so that the bolts 28 carryout a relative movement with regard to drum 11. In view of this relativemovement, the chucks 17 are moved toward the workpiece 25 until theyengage the circumference of said workpiece. As soon as the chucks 17 bymeans of their clamping surfaces 23 engage the workpiece 25, the controldisc 29 is turned against the force of the brake band 35. When thisoccurs, the chucks 17 will, as described above, with increasing torquepress against the circumference of the workpiece with increasingpressure. The clamping surfaces 23 of the chucks 17 are in thesecircumstances engaging the circumferential surface of the workpiece 25in such a way that a kind of elbow lever is formed the elbow joint ofwhich is represented by the supporting area 38. I

Since the clamping jaws or chucks 17 of the two chucks 5, 6 are movableindependently of each other, the workpiece guided by the two chucks 5, 6is safely held at two areas.

The hollow shaft 15 which has both ends journaled in friction bearingsis within the bearing housing 4 provided with a disc-shaped flange 39the outer side of which has fixedly screwed thereto a worm wheel 40. Aworm 41 meshes with the worm wheel 40, said worm 41 being rotatablyjournaled about a vertical axis adjacent the bearing housing 4. Worm 41is drivingly connected through an elastic plug clutch 42 with a flangedelectric motor 43 which is located below said clutch 42 and is arrangedat one side of the support 3. By means of motor 43 the chucks 5, 6 arerotated in the manner described above.

FIGS. 35 illustrate the thread cutting device 8 of the apparatusaccording to F IG. 1. This thread cutting device 8 comprises a housing44 having pivotally mounted therein a bearing ring 45 which is coaxiallyarranged with regard to the chucks 5 and 6 and which is adapted to bearrested by means of a tommy screw 46. To this end, the housing 44 inthe embodiment shown in FIGS. 3 and 4 has its top side provided with aslotlike recess 47. The tommy screw 46 which threadedly engages thebearing ring 45 rests through the intervention of a corresponding sleeve48 on the marginal areas of the recess 47. The marginal zone of slot 47may be provided with a scale for facilitating the adjustment of thebearing ring 45. A control disc 49 is rotatably journaled in the bearingring 45, said control disc being provided with a passage 50. The topside of the control disc 49 is at the circumference provided with asemicircular groove-shaped recess 51 for receiving a pressure spring 52.One end of pressure spring 52 rests on a bolt 53 in the bearing ring 45whereas the other end of said spring 52 rests on a bolt 54 in thecontrol disc 49.

Cutting jaw holders 55 are provided at that end face of the housing 4which faces the chucks 5, 6. These cutting jaw holders 55, preferablyfour, are uniformly distributed over the circumference and form radialsliding guides for the cutting jaws 56 respectively. The cutting jaws 56by means of a pin 57 extend through corresponding recesses or cutouts inthe end wall of the housing 4 and are guided in grooves 58 at thecorresponding end face of the control disc 49. The three grooves 58 ofthe control disc 49 partially follow a spiral transverse to thecircumferential direction of the control disc 49 and curved toward thecenter thereof in such a way that the inner ends of the grooves 48 pointin a direction opposite to the direction of the pull exerted by thesprings 52 upon the control disc 49. When the control disc 49 is turnedrelative to the housing 44, the cutting jaws 56, which are guided bypins 57 in the grooves 58 of the control disc 49, carry out a radialmovement.

The bearing ring 45 and the control disc 49 may in the cutting positionof the cutting jaws 56 be arrested relative to each other by anarresting device 59. This arresting device 59 has a rotatably journaledabutment roller 60 on the bearing ring 45 and an abutment roller 61 onthe control disc 49. The innermost mantle line of the abutment roller 60of the bearing ring 45, which mantle line points toward the central axisof the threading die head, is located approximately on the same sweepcircle as the outermost mantle line of the abutment roller 61 of thecontrol disc 49, the arrangement being such that these two rollers 60,61 can just be moved past each other when the disc 49 is turned towardthe bearing ring 45. The bearing ring 45 has a cage for a spacer member62 formed by a cylindrical member. This cage is radially formed by atwo-arm lever 63 and a pin 64 and at the sides perpendicular thereto isformed by the walls of a cut 65 at the circumference of the bearing ring45. ln its starting position, the spacer member 62 engages a supportingsurface 66 of one arm 67 of the two-arm lever 63. When the lever 63,which is pivotable in the cut 65 of the bearing ring 45 about a pivot68, is with its arm 67 pivoted toward the control disc 59, the spacermember 62 is moved toward the two abutment rollers 60, 61 in such a waythat it is centered between said two rollers. When continuing thetilting movement of lever 63, the spacer member 62 is moved between theabutment rollers 60, 61 which move away from each other, until itscentral axis is in alignment with the central axes of the abutmentrollers 60, 61. For purposes of moving the abutment rollers 60, 61 awayfrom each other, it is merely necessary to turn the control disc 49relative to the housing 44 in the direction of the arrow 69 in such away that the pins 57 of the cutting jaws 56 move into radially furtherinwardly located areas of the grooves 58 of the control disc 49 and thusthe cutting jaws move to their cutting position. In this cuttingposition, the cutting jaws 56 are then held by spacer member 62 which islocated between the abutment rollers 60, 61. For purposes offacilitating the introduction of the spacer member 62 between theabutment rollers 60, 61, the other arm 70 of the two-arm control lever63 is provided with a follower 71 in the path of movement of which thereis located one marginal area of a cut 72 at the circumference of thecontrol disc 49 in which cut the abutment roller 61 is journaled. Whentilting the control lever 63 in the opposite direction, the follower 71first moves the control disc 49 in the direction of the arrow 69 untilthe spacer member 62 engages the already partially moved apart abutmentrollers 60, 61 whereupon the remaining tilting movement of the controldisc 49 in the direction of the arrow 69 is effected by pressing thespacer member 62 between the rollers 60, 61. In this condition, thefollower 71 no longer engages the control disc 49.

The concave surface 75 of the one-arm lever 74 linked to the housing 44at 76 engages the outer side of an arm which pertains to the controllever 63 and carries a pressure roller 73. The radius of the curvedsurface 75 of the lever 74 corresponds approximately to twice the sweepradius of the outer mantle line of the pressure roller 73 so that thecontrol lever 63 can equally well be actuated through the interventionof lever 74 in each of its possible positions relative to the housing44. That side of the lever 74 which faces away from the curved surface74 is engaged by a cam 77 of an actuating shaft 78 which is rotatablyjournaled on the housing 44 for rotation about an axis parallel to theaxis of the threading die head. One end of shaft 78 which protrudes fromthe housing 44 has a radial arm 79 with a handle 80. By turning theactuating shaft 78 by means of the handle knob 80, the lever 74 istilted toward the control lever 63 so that the control disc 49 is movedin the above-mentioned manner to its cutting position and is held inthis position by the arresting device 59. The lever 74 and the cams 77are protected within the housing 44.

That side of the abutment rollers 60, 61 which faces away from thecontrol lever 63 has tiltably linked thereto in the cut 72 of thecontrol disc 49 a disengaging lever 81, the pivot being indicated by thereference numeral 82. That side of lever 81 which faces away from thepivot 82 is provided with a cutout 83 having resting therein an abutmentpin 84 connected to the control disc 49 so that the disengaging lever 81is in both possible tilting directions limited by a single abutment 84.When the spacer member 62 occupies a position between the abutmentrollers 60, 61, the disengaging lever 81 is tilted to its end positionwhich is located toward the axis of the control disc 49. When thedisengaging lever 81 is now tilted toward the spacer member 62 locatedbetween the rollers 60, 61 this spacer member will be pressed toward thelever 63 which means the spacer member is removed from between theabutment rollers 60, 61, so that the control disc 49 in view of thethrust of pressure spring 52 is turned in a direction counter to thedirection of the arrow 69 until the bolt 53 abuts one end of the recess51 and the cutting jaws 56 are in their starting position.

That side of the disengaging lever 81 which faces away from the abutmentrollers 60, 61 is engaged by an end of the feeler pin 85 which isradially displaceable with regard to the axis of the threading die headin a corresponding bore of the control disc 49.

A runup abutment 86 with a corresponding cylindrical section 87 isaxially displaceably guided on that side of the cutting jaws 56 whichfaces away from the chucks 5, 6. This abutment 86 is displaceably guidedon the housing 44 or the control disc 45 at the axis of rotationthereof. The cylindrical section 87 of the abutment 86 is provided witha circumferential groove 88 one wall of which is conical. The mantlelines of this conical section converge from the abutment 86 away in aconical manner in such a way that a control surface 89 is formed whichis engaged by the feeler pin by means of its radially inwardly andconically designed end 90. The abutment 86 which is advantageouslyformed by a platform-shaped diametrical web, has a stair-shaped abutmentsurface in such a way that workpieces 25 of different diameters may abutagainst a pertaining abutment surface. The staging of the abutmentsurface may be selected in conformity with the German Standard DlN 2999governing the length of threads on pipes of different diameter. When theworkpiece 25 which during the thread cutting operation carries out anaxial advancing movement, abuts against the abutment 86, the saidabutment is moved by the workpiece 25 during its further movement. As aresult thereof, the feeler pin 85 engaging the conical control surface89 of the abutment 86 is moved radially outwardly while moving thedisengaging lever 81 in the corresponding tilting direction so that inthe above mentioned manner the spacer member 62 is pushed out frombetween the abutment rollers 60, 61 and the control disc 49 is by thepressure spring 52 tilted into its FIG. 3 position in which the cuttingjaws 56 are moved radially outwardly which means disengage the workpiece25. As a result thereof, automatically the thread cutting operation isinterrupted when a certain preset thread length has been obtained.

One arm 92 of a two-arm lever 91 linked at 93 to the housing 44 islinked to the outside of the housing 44, said linkage point beinglocated on that side of the cylindrical section 87 which faces away fromthe abutment 86. The other arm 94 of lever 91, which arm has one end 95thereof fork-shaped, extends around that end of the actuating shaft 78which faces away from the handle 80 and likewise protrudes from thehousing 44. Shaft 78 has the said end provided with a broadened collar69 which is formed by a sleeve. The actuating shaft 78 is displaceablymounted in the housing 44 in axial direction so that by displacement ofthe actuating shaft 78 in the direction of the arrow 97, the abutment 86may by means of the lever 91 be displaced in precisely the samedirection in which it is displaced by the oncoming workpiece 25. In themanner described above, the spacer member 62 is pushed out from betweenthe abutment rollers 60, 61 so that the thread cutting operation can beinterrupted manually independently of the position of the workpiece 25with regard to the abutment 86 by axially displacing the actuating shaft78 in the direction of the arrow 97. For purposes of displacing theactuating shaft 78, the radial arm 79 is tiltably journaled in a radialdouble-cone recess 98 of the actuating shaft 78 for tilting about anaxis 99 perpendicular to the actuating shaft 78. In spaced relationshipto the pivot axis 99, the radial arm 79 has on the housing 44 associatedtherewith a preferably adjustable bearing 100 so that by tilting theradial arm 79 in the direction of the arrow 101 toward the bearing 100,the actuating shaft 78 is tilted in opposite direction (arrow 75)whereby the cutting jaws 56 are returned from their cutting position.The device, for instance the support 3, may furthermore at a suitablelocation and at that side of the arm 79 which is located opposite to thebearing 100 be provided with a further preferably adjustable bearing102. This last-mentioned bearing is with regard to the axis of theactuating shaft 78 located radially outwardly of the bearing 100 sothat, when the radial arm 79 which pertains to the head 8 carrying out adisplacement movement during the cutting operation moves against thebearing 102, the cutting jaws 56 will in the manner described above bemoved outwardly by the tilting movement of the radial arm 79. Thisdesign is particularly suitable for cutting long threads which do notinvolve the abutment 86 but in the course of which the workpiece 25 canpass unimpededly through the housing 44. The abutment position of theabutment 86 is determined by a protrudingextension 103 which in theabutment position of the abutment 86' will under the influence of aspring 104 engage the outside of the housing 44.

According to the embodiment shown in FIGS. 3 and 4, the actuating shaft78 is provided at the bottom side of the housing 44 of the head 8whereas the tommy screw 46 for the adjustment of the depth of the threadis arranged at the top side of the housing 44. As will be seen from FIG.1, the actuating shaft 780 with the radial arm 79a carrying the handle80a may also be provided on the top side of the housing 44a.

The guiding means 7 on the support 3 for the head 8, the pipe-cuttingdevice 9'and the deburring device are formed by a cylindrical rod 105 atone side and by a sliding and supporting surface 106 on the other sideof the support 3. The rod 105 is at that end thereof which faces awayfrom the chucks 5, 6 held in a supporting plate 107 by means of atapered extension. Plate 107 is detachably in centered positionconnected to the end face of the support 3 by means of screws 108. Aguiding sleeve 109 is displaceably guided on the cylindrical rod 105.Placed on said guiding sleeve 109 by means of an extension 110 is thehousing 44, 441 of the thread cutting device 8. The said extension 110may, in conformity with FIG. 3, be formed by a part which is detachablefrom the remaining portion of the housing 44 so that thethread-cuttingdevice 8 can be removed from the support 3 without removing the sleeve10 from the rod 105. The pipe-cutting device 9 is by means of acorresponding sleeve-shaped extension 111 placed upon the guiding sleeve109. This sleevelike extension 111 rests on one side upon a collar 112of sleeve 109 and on the other side rests against a spacer sleeve 113.This spacer sleeve 113 is located between the thread-cutting device 8and the pipe cutting device 9 and is centered relative to the sleevelikeextension 110 of the device 8 by a corresponding annular protrusion. Thedeburring device 10 likewise comprises a sleeve-shaped extension 114 bymeans of which it is placed as last part upon the guiding sleeve 109.The sleeves 110, 111, 1 13 and 1 14 are held in their respectivepositions by a spring ring 115.

The devices 8- 10 are by means of corresponding sliding surfaces restingon the sliding surface 106 of the support 3. As will be seen from thethread-cutting device 8 of FIG. 4, the housing 44 and, morespecifically, that side thereof which is located opposite to thesleeve-shaped extension 110 has a downwardly directed narrow slidingsurface 116 which when the thread cutting device 8 is installed rests onthe supporting and guiding surface 106 of the support 1.

lt is, of course, to be understood that the present invention is, by nomeans, limited to the specific construction shown in the drawings butalso comprises modifications, the invention being determined by thescope of the appended claims.

1 claim:

1. An apparatus for machining pipes and the like, especially for threadcutting, deburring or cutting off and comprising in combination: aframe, rotary clamping means on the frame for receiving a workpiece andoperable to drive the workpiece in rotation, machining head means on theframe reciprocable thereon in the direction of the axis of said clampingmeans and having cutting means therein including cutting means moveablethereon in a direction transverse to the axis of said clamping means,each said clamping means comprising a plurality of one-arm levers eachpivoted at its radially outer end to said clamping means and having itsradially inner end inclined to form workpiece engaging means, saidclamping means further comprising a housing in which the respectiveonearm levers are mounted, each lever having a rounded radially outerend and said housing having a rounded socket on its periphery forreceiving each said rounded outer end, each said lever having anintegral pin-shaped extension projecting laterally from both sidesthereof, said extension being coaxial with said rounded radially outerend of the lever, recess-forming means in said housing loosely receivingsaid extension, said housing being drumlike and having a cover platemounted on its open side, a

control member coaxial with each clamping means and rotatable relativethereto, a recess in each one-arm lever between the ends thereof, andmeans on the control member pertaining to the respective clamping meansengaging the said recess for tilting of said lever in response torotation of said control member relative to said clamping means.

2. An apparatus in combination according to claim 1 in which saidhousing has a closed periphery, the control member for each clampingmeans being rotatably journaled on the sidewall of said housing thereofwhich is integral with the periphery of the housing, said recess in eachonearm lever being in the form of a slot extending radially to the axison which the lever is pivoted to said housing, each control membercomprising a cylindrical portion, and adjustable friction means carriedby said frame and engaging said cylindrical portion.

3. An apparatus in combination according to claim 1 in which saidclamping means comprise two axially spaced clamping devices bothindependently controlled and each adapted for driving engagement with aworkpiece, and means interconnecting both said clamping devices foruniformly distributed turning moment during rotation as a unit.

4. An apparatus in combination according to claim 1, which includesfirst rodlike guiding means on the frame extending parallel to the axisof a workpiece being machined and pivotally supporting said machininghead means, a second guiding means on said frame spaced from said firstguiding means and presenting a sliding surface parallel to saidworkpiece axis, said machining head means including surface means forengagement with said sliding surface to support said machining headmeans in working position while permitting the machining head means tobe tilted on said first guiding means out of working position, saidmachining head means comprising a cut off head and a threading head anda delivering head and each thereof being individually tiltable on saidfirst guiding means, said machining head means including brushing meansrotatable receiving said first guiding means.

1. An apparatus for machining pipes and the like, especially for threadcutting, deburring or cutting off and comprising in combination: aframe, rotary clamping means on the frame for receiving a workpiece andoperable to drive the workpiece in rotation, machining head means on theframe reciprocable thereon in the direction of the axis of said clampingmeans and having cutting means therein including cutting means moveablethereon in a direction transverse to the axis of said clamping means,each said clamping means comprising a plurality of one-arm levers eachpivoted at its radially outer end to said clamping means and having itsradially inner end inclined to form workpiece engaging means, saidclamping means further comprising a housing in which the respectiveone-arm levers are mounted, each lever having a rounded radially outerend and said housing having a rounded socket on its periphery forreceiving each said rounded outer end, each said lever having anintegral pin-shaped extension projecting laterally from both sidesthereof, said extension being coaXial with said rounded radially outerend of the lever, recess-forming means in said housing loosely receivingsaid extension, said housing being drumlike and having a cover platemounted on its open side, a control member coaxial with each clampingmeans and rotatable relative thereto, a recess in each one-arm leverbetween the ends thereof, and means on the control member pertaining tothe respective clamping means engaging the said recess for tilting ofsaid lever in response to rotation of said control member relative tosaid clamping means.
 2. An apparatus in combination according to claim 1in which said housing has a closed periphery, the control member foreach clamping means being rotatably journaled on the sidewall of saidhousing thereof which is integral with the periphery of the housing,said recess in each one-arm lever being in the form of a slot extendingradially to the axis on which the lever is pivoted to said housing, eachcontrol member comprising a cylindrical portion, and adjustable frictionmeans carried by said frame and engaging said cylindrical portion.
 3. Anapparatus in combination according to claim 1 in which said clampingmeans comprise two axially spaced clamping devices both independentlycontrolled and each adapted for driving engagement with a workpiece, andmeans interconnecting both said clamping devices for uniformlydistributed turning moment during rotation as a unit.
 4. An apparatus incombination according to claim 1, which includes first rodlike guidingmeans on the frame extending parallel to the axis of a workpiece beingmachined and pivotally supporting said machining head means, a secondguiding means on said frame spaced from said first guiding means andpresenting a sliding surface parallel to said workpiece axis, saidmachining head means including surface means for engagement with saidsliding surface to support said machining head means in working positionwhile permitting the machining head means to be tilted on said firstguiding means out of working position, said machining head meanscomprising a cut off head and a threading head and a delivering head andeach thereof being individually tiltable on said first guiding means,said machining head means including brushing means rotatable receivingsaid first guiding means.